Stanislav Petrov was credited with helping prevent US-Russia nuclear war.
Petrov dismissed a warning about US nuclear strike as a false alarm.
The probe proved that Petrov was right.
Stanislav Petrov, a Soviet military officer who is widely credited with helping prevent a nuclear war with the United States, has died aged 77, his son said on Tuesday.
Petrov, whose extraordinary story was told in a documentary titled “The Man Who Saved the World”, received several international awards, was honoured at the United Nations and met Hollywood superstars such as Robert De Niro and Matt Damon.
He left the military in 1984 and settled in the town of Fryazino some 20 kilometres (12 miles) northeast of Moscow. Petrov died in relative obscurity on May 19 at the age of 77.
In September 1983, Petrov was an officer on duty at a secret command centre south of Moscow when an alarm went off signalling that the United States had launched intercontinental ballistic missiles.
The officer — who had only a few minutes to make a decision and was not sure about the incoming data — dismissed the warning as a false alarm.
Had he told his commanders of an imminent US nuclear strike, the Soviet leadership — locked in an arms race with Washington — might have ordered a retaliatory strike.
Instead the 44-year-old lieutenant colonel reported a system malfunction and an investigation that followed afterwards proved he was right.
Several months later Petrov received an award “for services to the Fatherland”.
Petrov’s story only came to light after the fall of the Soviet Union in 1991.
“My father could not have cared less. He was always surprised that people were making a hero out of him,” said his son.